This invention relates to the field of door security systems. More specifically, this invention relates to the use of a push or exit bar for securing a doorway.
Push bars or exit bars which allow egress through a doorway while limiting ingress are well-known components of door security and emergency systems. The conventional exit bar is mounted on the interior side of the door to be secured and is oriented generally horizontally across the face of the door. A push force on the bar toward the door face operates a door latch to permit opening of the door. Conventional exit bars typically employ a mechanical linkage to actuate the latch mechanism for unlatching the door. Exit bars may also employ mechanical locks to secure the door from opening. A handle can be additionally provided on the exterior face of the door to allow ingress under certain circumstances. Exit bars have also been connected with alarm systems to warn security personnel of a door opening.
Conventional exit bar systems while enjoying great popularity have also exhibited a number of deficiencies. For example, to secure an exit bar from operating the associated latch may require individually manually locking each bar. For most applications, it is generally undesirable for safety reasons to permanently lock exit bars. Even when a building has low occupancy, there may be times when for emergency reasons, exit doors should not be secured in a permanent fashion that would inhibit egress.
During periods of high traffic levels through a doorway, mechanical latch mechanisms of a conventional exit bar can experience a high rate of wear. To reduce wear on mechanical latch components, some conventional exit bars may be manually locked in a dogged position wherein the latches remain in a retracted state. However, each bar must be directly manually dogged and undogged at the site of the door.
Similar problems arise with regard to exit bar systems that employ an auxiliary outside handle to allow selective ingress to a secured area. The operative mode of these outside handles must be generally individually manually changed by visiting the exit bar installation to set the desired mode.
In more advanced systems, alarms have been connected to exit bars to generate audible or visible indications when an egress is attempted. These alarms are generally not sophisticated in distinguishing between permitted and unpermitted egresses. In health care facilities, alarms may also be used to indicate attempts by patients to egress the facility. Such alarms are particularly important in facilities where patients may need monitoring or assistance in egressing. For example, in facilities caring for patients lacking full mental or physical competence, such as nursing homes or child care facilities, egress for some individuals should be prevented in other than emergency situations. However, a deficiency of many conventional exit bars is to allow immediate egress even when the exit bar is combined with an alarm. This may permit unauthorized personnel or patients to immediately exit a secured area.
Attempts have been made to combine exit bars with various forms of door locking and security systems to overcome some of the above-mentioned problems. Such hybrid systems, however, tend to result in excessive costs and complexity. Such combination lock systems may require mounting not only the exit bar, but also mounting an auxiliary lock system to the secured door.
Exit bars further can exhibit a deficiency common to many electronic lock systems. Typically, a large number of wires are required to be installed across the hinge connecting the door and door frame in order to provide a large number of functions for the exit bar. A single function may require two or three individual wires. The electrical connections across the hinge often necessitate special hardware and cable covers to hold the wires. These special materials can increase installation costs and reduce operating reliability.